Bone density of élite female athletes with stress fractures

Do More Highly Organized Collagen Fibrils Increase Bone Mechanical Strength in Loss of Mineral Density After One-Year Running Training?

“…The correlation between BMD and fracture risk is reported to be high (3‐5,10,36) . However, there are reports that suggest that density measurements do not always relate to the strength of cancellous or cortical bone (37‐39) and that other factors than bone density contribute to the mechanical behavior of bone. A significant reduction of trabecular bone density with no alteration in the strength properties has been reported in ovariectomized beagles (40) and orchiectomized rats (41) .…”

“…Collagen orientation has been reported to be closely correlated with the mechanical properties of cortical bone, accounting for 71% of the variation in ultimate tensile stress and 58% of the variation in the elastic modulus of equine radius, while porosity and BMD have been found to correlate less strongly with strength (43) . Furthermore, stress fractures in female athletes have been reported to be largely independent of BMD (38) . It has been claimed that reorganization of the bone matrix, induced by exercise, may guarantee the maintenance of strength despite the loss of mineral density, (44) and we suggest that this may be the mechanism for the properties of the bones in the present study.…”

Simulated effects of marathon training on bone density, remodeling, and microdamage accumulation of the femur

“…It is believed that the etiology of stress fractures involves increased fatigue microdamage and excessive bone remod eling [11][12][13][14]. Although there has been no evidence of changes in serum and urinary bone turnover markers for athletes with stress fractures [15][16][17], Mori et al [14] dem onstrated histological evidence of local microdamage accu mulation and bone remodeling at the site of a stress fracture. In their study, Mori et al [14] found increased woven bone formation and a highly porous cortex, indicat ing excessive remodeling activity, in a bone biopsy from the site of a stress fracture.…”

“…The simulation combined a finite element model of the femur with a previously devel oped bone remodeling algorithm that accounted for the biological response of bone cells to the mechanical environ ment of bone [18,19]. Here, we examined the influence of 16 week beginning, intermediate, and advanced marathon training programs on microdamage accumulation and remodeling in the femur. It was expected that the simula tion would show variations in regional remodeling activity and microdamage accumulation, and therefore fracture risk, as one progressed from the beginning to the advanced training schedules.…”

Pubic Stress Fracture in a Collegiate Lacrosse Player

“…10 Lower bone mineral density (BMD) in female athletes, compared to that of male athletes, may increase the risk of stress fracture. 11,12 No menstrual dysfunction or eating disorder was involved in this case, but assessment of BMD, menstrual function, and dietary habits should be considered when evaluating a female athlete who is suspected of having a stress fracture.…”